The rumors were true: Sarah Palin endorsed Donald Trump Tuesday in a joint appearance at Iowa State University in Ames. And now that we’ve seen the Maverick Duo onstage, and heard Ms. Palin’s harsh critique of the Republican establishment, their political relationship perhaps makes more sense than it did at first news flash.

Indeed, there are good reasons why Palin ended up with Mr. Trump, as opposed to tea party favorite Ted Cruz.

The first is that they appear to be ideologically in sync. As frustrated Cruz supporters pointed out all afternoon, Trump does not have a history of committed conservative positions. Yes, he wants a wall on the Southern border, but he’s also said kind things about single-payer health care and mused about higher taxes on the rich. He used to be a Democrat.

So why would the self-declared Mama Grizzly of the GOP pick him?

Because she is not that conservative herself, that’s why. Her address in support of Trump was not a list of right-leaning positions taken and liberal bills opposed in the manner of a Cruz stump speech. It was an expression of populist anger, à la Trump. In the past, Palin has called herself a feminist and even supported a pathway to citizenship for illegal immigrants, points out political expert Harry Enten at FiveThirtyEight. In terms of actual policy positions, she’s no Senator Cruz, or even a Marco Rubio. She’s a moderate conservative.

Second, Palin and Trump focus a lot of their ire on a common enemy: the GOP establishment. The party’s Powers That Be have acquiesced to President Obama, in their view, and simply allowed Obamacare and other “outrages” to occur, despite their House and Senate majorities. They are bought and paid for by donors, and then do the donors’ bidding, Palin said in her remarks Tuesday.

Trump’s “been able to tear the veil off this idea of the system – the way that the system really works,” she said.

Yes, Cruz targets the establishment, too, but he is an elected senator, and thus can’t be a true outsider in Palin and Trump’s terms. Plus, Palin and Trump reject the notion that party leaders have a right to lecture anyone about what it means to be conservative, or even a Republican.

Cruz and Senator Rubio are trying to win the nomination board game by playing within the existing rules and manipulating existing ideological pieces. Trump – endorsed by Palin – is just tossing the board aside and making up new rules and his own political philosophy as he goes along.

“They’re concerned about this ideological purity? Give me a break!” said Palin at one point in Ames.

Even if Trump loses, there’s probably no return to the old, predictable definition of what it means to be “conservative.”

Finally, Trump and Palin have the same style. Both are walking streaks of bluster. They express anger and disillusionment onstage in a sort of looping speaking style that relies on moving from prepared one-liner to prepared one-liner via extemporaneous paragraphs that don’t always make sense.

To see them onstage together is to recognize a professional couple in the making, like seeing Fred Astaire and Ginger Rogers dance for the first time, or Jennifer Lawrence meet Bradley Cooper at the beginning of the movie.

Not everyone thinks this is a good thing, of course. At the National Review, Charles C.W. Cooke judges Palin’s endorsement of Trump to be a melding of personality cults.

The pair has “convinced a significant portion of the American population that their personal advancement is the key to the country’s success. Together, just think how great America can be!” Mr. Cooke writes.